The present invention relates to a method of controlling torque in an automotive powertrain and in particular to a method of limiting torque during a regenerative mode of the automotive powertrain.
A hybrid powertrain of an automotive vehicle includes an electric machine. The machine may be operated in a propulsive mode where the machine rotates to produce a torsion force that propels the vehicle. Alternatively, the machine may be operated in a regenerative mode to brake the vehicle and produce an electrical charge that is stored in a battery. During the regenerative mode, a torque converter clutch may need to be locked to transmit kinetic energy through the powertrain to the machine. To facilitate opening the torque converter clutch when exiting the regenerative mode, a transmission controller may set a regenerative torque limit based on the status of the torque converter clutch.
However, the status of the torque converter clutch used by the transmission controller to set the regenerative torque limit may be less accurate than desired.